uniQure recently announced updated clinical data for three patients who have been treated with AMT-061, the company’s investigational gene therapy for patients with severe and moderately severe hemophilia B. AMT-061 consists of adeno-associated virus serotype 5 (AAV5), which has been demonstrated to be safe and well-tolerated, acting as a delivery vector carrying a gene cassette with the Padua variant of factor IX (FIX). New data was presented at the Hemostasis & Thrombosis Research Society (HTRS) 2019 Scientific Symposium on May 10, 2019 in New Orleans.

The ongoing trial is a phase IIb multi-center study designed to evaluate participants who have received a single dose of AMT-061. Enrolled patients will be monitored for 52 weeks to assess FIX activity, bleeding rates and usage of FIX replacement therapy. Trial participants will also be followed for five years post-treatment to evaluate the safety of AMT-061.

According to a uniQure press release, the new data show that all three patients have demonstrated “increasing and sustained” FIX levels after a one-time administration of AMT-061, with two of the three patients reaching FIX activity in the normal range. Mean FIX activity for the three patients at six months after administration increased to 47% of normal. The first patient achieved FIX activity of 51% of normal, the second patient achieved FIX activity of 33% of normal, and the third patient achieved FIX activity of 57% of normal.

“We believe these to be striking clinical data that show AMT-061 has the potential to deliver consistent and sustained increases in Factor IX activity into the range considered normal,” stated Robert Gut, MD, PhD, chief medical officer of uniQure. “Importantly, results across all patients in this study, even those that previously screen-failed other gene therapy studies, show no loss of FIX activity, no bleeding events and no need for infusions of FIX replacement therapy through six months after administration. Further, AMT-061 continues to be safe and well tolerated, with no patients requiring immunosuppression related to the therapy.” 

Source: uniQure press release dated May 10, 2019